Although funny animal does not have to be funny, it usually is, and caped critters often have a feature that both plays on their power potential and their name to humorous effect. Underdog springs to mind.
Apart from Joe Casey quips in the Stan Lee tradition, superheroes regularly receive comedic treatment. From normalman, powerless in a world of supertypes to Megaton Man whose exaggerated bulk is reminiscent of those Image titles where everything is drawn large.
Of the other genres that the superhero crosses over with, Ka-Zar may be the token 'Aryan in the jungle' for today's mighty world of Marvel but the one true crossover character is Black Panther.
Having not given sword and sorcery its own entry yet I feel sheepish mentioning Sword of the Atom and that may not be the only reason.